Conductor protecting tap clamp



Feb. 1, 1938.

CONDUCTOR PROTECTING TAP CLAMP Filed Jan. 22, 1937 JNVENTOR Q 242 W Pm-BY (L-Mm 194M ATTORNEY R. R. PI TTMAN El AL 2, 7,061

Ph edra. 1, 1938 2,107,061 connncron raornormc TAP CLAMP Ralph n.Pittman and Carroll n. ,Walsh, Pine Bluff, Ark.

Application January 22, 1937, Serial No. 121,812

40laims.

the same material, or of such material that galvanic or electrolyticaction due to the dissimilar metals will be so small as to have anegligible practical effect on the conductor. requires a different clampfor each conductor material.

It is an object of the present invention to provide means for using onetype of clamp for all conductor metals. v

Also, itis present practice to removably attac such a condition theconductor may be damaged by arcing, burning and pitting, or its tensilestrength lowered by annealing.

It is an object of the present invention toprovide means whereby theconductor cannot be damaged by arcing which occurs when a load isconnected or disconnected from a conductor due to the attaching orremoving of the live line clamp.

More specifically, it is an object of the invention to provide, incombination with a live line clamp, a conductor protecting member orsleeve which is removably attached to the clamp, means for permanentlyattaching the protecting sleeve to the conductor in response to thetightening of the clamp, and. means for removing the clamp from theprotecting sleeve following its application to the conductor asdescribed.

Another object is to provide a bimetallic sleeve as above describedinwhich the metal portions of the member which are respectively inphysical and electrical contact with the clamp and the conductor areelectrically compatible with the metals of the latter members.

With these and such other objects in view as may later appear, ourinvention resides in the novelform, arrangement and combination partsforming the device.

In the drawing (1 sheet): Fig. 1 illustrates a side elevational view ofthe device just prior to its application to a conductor; Fig. 2illustrates the device following its application tothe conductor; Fig. 3is a fragmentary sectional view taken along the line III-III in Fig. 1;Figs. 4 and 5 are respectively front and side elevational views of theconductor protecting member; and Fig. 6 shows the appearance of theconductor protecting member following the removal of the clamp.

60 Referring in detail to the drawing, the live line This practice 7 theclamp directly to the conductor, and under of the clamp shown in Figs. 1and 2 includes the body portion ll, having the inverted V-shaped portionis arranged to cooperate with the shoe M, between which an object may beclamped through the rotation of the screw eye l3. For convenience inapplying the clamp to energized conductors, the upper end of the clampis provided with the eye l2. A tap wire l5 attached in any suitablemanner to the body portion I l. I At a point along the line of movementof the shoe M, a pair of inwardly extending slots I8 are provided. Theseslots are arranged for supporting on the clamp the conductor protectingmember l6, shown more in detail in Figs. 3, 4, and 5. The conductorprotecting member I6 is formed from a flat ductile metal 'strip,.beingbent over at its upper end to fit in the V-shaped portion i9 of theclamp, and at its lower end to conform to the inner portion of the uppersurface of the shoe it. For mounting the conductor protecting member onthe clamp, a pair of spaced projecting portions Ii of the member, cutand bent outwardly therefrom, are arranged to extend throughthe slots IQof the body portion of the clamp. To insure retention of the conductorprotecting member in place on the clamp, the outermost ends of theportions ll may be bent either downwardly or upwardly with respect tothe body portion of the clamp.-

With the conductor protecting member in position on the clamp as justdescribed, it may be applied to the conductor it in the positionillustrated in Fig. l by means of insulated or live line sticks. Thescrew eye l3-is then rotated by means of a suitable insulated tool in adirection to move the shoe M upwardly toward the conductor it. In sodoing, the inner upper surface of the shoe first engages the outwardlybent lower portion of the conductor protecting member I6, and as themovement of the shoe is continued,

the conductor protecting member 85 is wrapped around the conductor,finally assuming the posi. tion illustrated in Figs.- 2 and 6. As theshoe l4 passes the projections H, the latter are sheared ofi between theshoe and the body portion of the clamp. l p 7 After the elements havetaken the position shown by Fig. 2 following the application of theclamp, the latter may now be repeatedly removed and applied withoutfurther disturbing the conductor protecting member Hi, the latterremaining permanently on the conductor in the position shown by Fig. 6.It will be seen that any arcing or metal burning incident to theelectrical connection of the tap wire IE to the line conductor It willoccur on the outside surface of the conductor protecting'member, and noton the con-. ductor. Any arcing on the conductor is highly undesirable,since it is normally under tension,- and may not only be weakened by theburning away or pitting of the metal, but also by annealing and thusweakening its tensile strength.

The above described arrangement solves the problem of damage to theconductor, regardless of the material of the conductor, clamp, orprotecting member, and in this manner one of the objects of theinvention is accomplished.

The solution to the problem of preventing damage to the conductorthrough arcing is an important object of the invention, but stillanotherproblem is solved by our invention.

The conductor protecting member l6 may be made of a bimetallic strip,and is so indicated in Fig. 5 of the drawing, but it is clear that it isnot necessarily bimetallic to solve the conductor burning problem, andthe present invention therefore embraces a protecting member of either asingle metal, or a bimetallic member.

The conductor protecting member is bimetallic only in the'event that thematerial of the conductor is electrically incompatible with respect tothat of the clamp. For the purpose of this invention, metals areelectrically incompatible, electrolytically incompatible" orincompatible if, when placed in abutting physical contact and carryingan electrical current under any atmospheric conditions, suiilcientgalvanic or electrolytic action occurs to damage either or both metals.For example, copper and aluminum are well known incompatible metals, andan alumi num conductor clamped in a copper clamp and completing anelectrical circuit will in a short time seriously damage both. On theother hand, high-copper brasses or bronzes are compatible with copper,and consequently these materials are widely used in the manufacture oflive line clamps. Again, zinc and copper are incompatible, therefore aclamp suited for copper conductors is unsuited for either an aluminum ora galvaze'd iron conductor. 1

These conditions of incompatibility have heretofore been recognized, andhave been met by the use of a diflerent clamp for use on aluminum,galvanized iron, and copper conductors, in each of which the conductorengaging portion is of a metal compatible with the metal of theconductor. Since all of the .above conductor materials have definiteeconomical applications in electrical utility construction, it hasheretofore been necessary for each utiliy to carry quantities of eachstyle oi. clamps in stock. Obviously their investment would be greatlyreduced, and their operations simplified, if one clamp could be adaptedfor all conductors, and this is another object of the present invention.

To illustrate specifically our solution to this problem, we may assumethat it is desired to have available only high copper content clamps,which in themselves are suited only for copper conductors. It is nowdesirable to connect a tap to an aluminum conductor. In this event, theconductor protecting member 16 will be bimetallic; that is, copper onthe outside, and aluminum on the inside, so that, when the adjustablemeans of the clamp is moved in a-direction to clamp the protectingmemberbetween the conductor and the clamp, only compatible metalsurfaces will be in contact. 'It is obvious that the conductorprotecting members are extremely low in cost as compared to the cost ofthe entire clamp, and since they are interchangeable on the clamp, avery considerable saving is eflected.

It should be understood that the two metals forming the conductorprotecting members are so united as to effectively exclude atmosphericmoisture, and that therefore no electrolytic action can occur within themembers themselves? From the above description it be clear that theproblem of preventing damage to theconductor from arcing is solvedregardless of the nature of the metals involved; also that both thisproblem and that of preventing damage from electrolytic action is solvedthrough the use of a suitable conductor protecting member.

While we have used quite specific language in describing our inventionherein, this has been done for the purpose of facilitating anunderstanding of the construction involved, and our invention is to belimited only as is necessitated by the claims and the prior art.

We claim, as our invention:

1. In a live line clamp having rotatively movable adjustable means forengaging a conductor, a conductor protecting member, means fordetachably mounting said member on said clamp, means responsive to therotary movement of said adjustable means in one direction for afiixingsaid protecting member to the conductor between the latter and saidclamp, and means responsive to rotary movement of said adjustable meansin the other direction for disengaging said clamp from its clampedposition with respect to said conductor protecting member.

2. In combination, a conductor, a metal clamp having adjustable clampingmeans for engaging said conductor, said clamp having a conductorengaging portion of a metal electrolytically incompatible with thematerial of said conductor, a bimetallic protecting member detachablymounted on the body portion of said clamp, said bimetallic member havingconductor and clamp abutting surfacesof metals respectively compatiblewith the material of said conductor and said clamp, and means responsiveto movement of said adjustable means for releasing said bimetallicmember from the body portion of said clamp, said movement afiixing andclamping said protecting member to the conductor in interposed relationto said clamp and said conductor so that only metal surfaces compatiblerespectively with the material of the conductor and the clamp are inphysical contact therewith.

3. The combination with a live line clamp having adjustable clampingmeans forremovably en- 4 gaging a conductor, a protecting memberdetachably mounted on the body portion of .said clamp,

clamp,-and means responsive to movement of said adjustable means forreleasing said member'i'rom the body portion of said clamp,' saidmovement permanently attaching said protecting member to the conductorand clamping saidmember between said conductor and said clamp. RALPH R.W.

CARROLL H. WALSH.

